Electric machines have a stator and a rotor both housed in a casing.
The stator has stator windings that are connected to phase rings in turn connected to bushings penetrating the casing.
Traditionally, the stator windings include one winding for each phase (FIG. 9) and the phase rings includes one conductor for each phase.
In order to increase the power output, a plurality of parallel windings for each phase can be provided (FIG. 10); likewise phase rings with a plurality of parallel conductors for each phase can be provided.
US 2007/0188030 discloses phase rings having three phases; each phase has three axially aligned parallel conductors made of curved bars or plates.
Cooling of the conductors is achieved by the gas (hydrogen or air) circulating within the electric machine.
These phase rings proved to be satisfactory during operation, nevertheless in order to further increase the electric power output, cooling should be improved.